notoneof and reverse operators.

lib/sparql/algebra/operator/notin.rb

@@ -6,7 +6,7 @@ class Operator
     # Used for filters with more than one expression.
     #
     # @example
-    #   (ask (filter (notin 2) (bgp)))
+    #   (ask (filter (notin ?o 1 2) (bgp)))
     #
     # @see http://www.w3.org/TR/sparql11-query/#func-notin
     class NotIn < Operator

lib/sparql/algebra/operator/notoneof.rb

@@ -13,8 +13,12 @@ class NotOneOf < Operator
       NAME = :notoneof
 
       ##
-      # XXX
-      #        
+      # Equivalant to:
+      #
+      #   (path (:x (noteoneof :p :q) :y))
+      #   => (filter (notin ??p :p :q) (bgp (:x ??p :y)))
+      #
+      # @note all operands are terms, and not operators, so this can be done by filtering results usin
       #
       # @param  [RDF::Queryable] queryable
       #   the graph or repository to query
@@ -30,6 +34,18 @@ class NotOneOf < Operator
       def execute(queryable, options = {}, &block)
         debug(options) {"NotOneOf #{operands.to_sse}"}
         subject, object = options[:subject], options[:object]
+
+        v = RDF::Query::Variable.new
+        v.distinguished = false
+        bgp = RDF::Query.new do |q|
+          q.pattern [subject, v, object]
+        end
+        query = Filter.new(NotIn.new(v, *operands), bgp)
+        queryable.query(query, options.merge(depth: options[:depth].to_i + 1)) do |solution|
+          solution.bindings.delete(v.to_sym)
+          debug(options) {"(solution)-> #{solution.to_hash.to_sse}"}
+          block.call(solution)
+        end
       end
     end # NotOneOf
   end # Operator

lib/sparql/algebra/operator/reverse.rb

@@ -13,7 +13,10 @@ class Reverse < Operator::Unary
       NAME = :reverse
 
       ##
-      # XXX
+      # Equivliant to:
+      #
+      #   (path (:a (reverse :p) :b))
+      #   => (bgp (:b :p :a))
       #        
       #
       # @param  [RDF::Queryable] queryable
@@ -30,6 +33,21 @@ class Reverse < Operator::Unary
       def execute(queryable, options = {}, &block)
         debug(options) {"Reverse #{operands.to_sse}"}
         subject, object = options[:subject], options[:object]
+
+        # Solutions where predicate exists
+        query = if operand.is_a?(RDF::Term)
+          RDF::Query.new do |q|
+            q.pattern [object, operand, subject]
+          end
+        else
+          operand(0)
+        end
+        queryable.query(query, options.merge(
+          subject: object,
+          object: subject,
+          depth: options[:depth].to_i + 1
+        ), &block)
+
       end
     end # Reverse
   end # Operator